Donald Judd met Dan Flavin in 1962 at a gathering in a Brooklyn apartment organized to discuss the possibility of a cooperative artist-run gallery. They exhibited together a year later when their work was included in New Work: Part I at Richard Bellamy’s Green Gallery, New York (January 8–February 2, 1963). As their mutual friend, the artist John Wesley, has said of their friendship, “[the two] became Flavin and Judd for a while. The two names were together.”1

Flavin was an avid draftsman, and drawing remained an essential part of his working process throughout his career. “All my diagrams, even the oldest, seem applicable again and continually. It is as though my system synonymizes its past, present and future states without incurring a loss of relevance.”2 This and the other right angle triangledrawing, both installed on the fourth-floor landing of 101 Spring Street, are mirror images of one another.